ceph/src/boost/boost/smart_ptr/detail/atomic_count_std_atomic.hpp

   1 #ifndef BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_STD_ATOMIC_HPP_INCLUDED
   2 #define BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_STD_ATOMIC_HPP_INCLUDED
   3
   4 //
   5 //  boost/detail/atomic_count_std_atomic.hpp
   6 //
   7 //  atomic_count for std::atomic
   8 //
   9 //  Copyright 2013 Peter Dimov
  10 //
  11 //  Distributed under the Boost Software License, Version 1.0.
  12 //  See accompanying file LICENSE_1_0.txt or copy at
  13 //  http://www.boost.org/LICENSE_1_0.txt
  14 //
  15
  16 #include <atomic>
  17 #include <cstdint>
  18
  19 namespace boost
  20 {
  21
  22 namespace detail
  23 {
  24
  25 class atomic_count
  26 {
  27 public:
  28
  29     explicit atomic_count( long v ): value_( v )
  30     {
  31     }
  32
  33     long operator++()
  34     {
  35         return value_.fetch_add( 1, std::memory_order_acq_rel ) + 1;
  36     }
  37
  38     long operator--()
  39     {
  40         return value_.fetch_sub( 1, std::memory_order_acq_rel ) - 1;
  41     }
  42
  43     operator long() const
  44     {
  45         return value_.load( std::memory_order_acquire );
  46     }
  47
  48 private:
  49
  50     atomic_count(atomic_count const &);
  51     atomic_count & operator=(atomic_count const &);
  52
  53     std::atomic_int_least32_t value_;
  54 };
  55
  56 } // namespace detail
  57
  58 } // namespace boost
  59
  60 #endif // #ifndef BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_STD_ATOMIC_HPP_INCLUDED